Image Credit: Sonja Flemming/CBS; Inset: John Shearer/Getty ImagesYou don’t have to be a genius to be psyched about this bit of casting news: Sources confirm to me exclusively that Judy Greer — perhaps the most endearing actress whose name you don’t know — has been tapped to appear in a May sweeps episode of The Big Bang Theory. Oh, and did I mention that her character spends the night with Sheldon? ‘Cause she does!

The big-screen second banana (in everything from The Wedding Planner to 27 Dresses) and recent Modern Family guest will play a famous physicist. (Wait, there are famous ones?) Adds executive producer Bill Prady: “Sheldon invites her to stay over at the apartment.”

Why?

Prady wouldn’t say. But as far as I’m concerned, it doesn’t matter. Where the erstwhile Miss Guided goes, I’m following. How about you? Excited? Fellow Greer lovers, fill in the uninitiated as I light a candle in hopes Fox will pick up her IRS pilot, Tax Man.